Machine for making noncircular tubing on continuously rotating arbors



Nov. 18, 1952 P M. PADGl-:TT 2,518,233

MACHINE FOR MAKING NONCIRCULAR TUBING 7 sheets-sheet l ON CONTINUOUSLY ROTATING ARBORS Filed Nov. 5 1948 INVENTOR 'BYQNMNWMK A Se NAM www ATTORNEYS Nov. 18, 1952 P. M. PADGETT 2,618,233

MACHINE FOR MAKING NONCIRCULAR TUBING 0N CONTINUOUSLY ROTATING ARBORS Filed Nov. 5, 1948 '7 Sheets-Sheet 5 INVENTOR \\hx "M NM 94 ATTORNEYS Nov. 18, 1952 P. M. PADGETT MACHINE FOR MAKING NONCIRCULAR TUBING ON CONTINUOUSLY ROTATING ARBORS 7 Sheets-Sheet 4 Filed Nov. 5, 1948 www ATTORNEYS Nov. 18, 1952 P. M. PADGETT f 2,618,233

MACHINE FOR MAKING NONCIRCULAR TUBING ON CONTINUOUSLY ROTATING ARBORS Filed Nov. 5, 1948 7 Sheets-Sheet 5 FIGB.

lNvEN ,OR

ATTORNEYS KAM Nov. 18, 1952 Filed Nov. 5, 1948 FIG.II.

P. M. PADGETT MACHINE FOR MAKING NONCIRCULAR TUBING ON CONTINUOUSLY ROTATING ARBORS 7 Sheets-Sheet 6 ATTORNEYS A `l Nov. 18, 1-952 P. M. PADGl-:TT

MACHINE: FOR MAKING NoNcIRcuLAR TUBING ON CONTINUOUSLY ROTATING ARBORS 7 Sheets-Sheet 7 Filed Nov. 5, 1948 INVENTOR A m N@ ATTORNEYS Patented Nov. 18, 1952 .1

v5 "f 'l 5". u This nventionrelates flexibleymetal;tubing.:-y-

,..1; It'y is ani :object of the invention tofprovide an improved machinefor making lmetal tubing-,by

.helicalls winding 4awpreformed;rnetalrstrip around a rotating mandrel, and particularly a mandrel of non-rectangular cross section havingftwo of its*@opposite. sidessubstantially longer than :the AOther twoppposite sides. f; xEAgmore-fspecic objectwf theinvention vis .to make4 helically wound, gexible metal tubing of rectangularfcrosstsection atv higher speed y thanhas Vbeen .possible onthe machinesof thepriorart, and to make such. tubing with .more uniform seams and with.less, scrap losses. .l

sible, the;A higher speed operation and' resulting greater production relates to. positive. displacement-means for moving guidingand seaming rolls both toward and away. from the. axis of r0tatio n ofthe mandrel. Such positive displacement means maintain the` rollers in contact Withthe .non -circularsurface of the tubing as it is formed on the mandrel. Y

Another object of the invention is to .provide atube makingimachine in which guiding and seaming'rollers located atangularly s'pacedregins` around the mandrel yproduce a progressive movement 'of the 'anged and folded edgesofthe preformed) strip in such a Way' that tearing andy cracking of theedges 'is eliminated anda locked .seam is formedwhile 'the rollers strip the tubing 'progressively 'from theL mandrel.' l Another feature vofthe invention relates to th n'f'anner in which a Wire is applied to the man- Adrelahead ofY the strip and inisuch a'vvayfasto eliminate anyvknks `and..irregularities inthe Wire 4:before thestripy is'laid on the mandrel 'over the "Wire:VA Another 'feature of `the Wire feed relates 'to thelappli'cation of substantially Auniform -tenf sion to lthe wire regardless of the diameterAof the supply reel from Which'the Wireis payed out. Otherobjects,l featuresfand advantages of the .invention will'appear or be'pointed outv as the Adetaken on the Enel-14 ofJFig'ure 3,

WMACHINE 'FoRffMAKINGvNoNoIRCULAR l f i -1 f TUBINGoN ooN'HNUoUsLYRoTA'r "J. a"corporationof Mas'sachus'ettsYl Y .I Appuc-ationNovember 5,1948, srialNaaam to machines:y for/making I 1 5 7,One featureof the invention which makespos- Fisureg is; en., .enlarged .detailed Yi'WfQf #He mandrel and. the. guiding' and eexnngoll fgr applying the Strip ,material 19th? Infiel, Figure 6 is. an enlarged. detail: View Partly in section, I of oneoithe. supporting arms guiding and seaming rolls,V

, Figur@ 'US @s etollal View -Q-.l of Fieu1e6- J .f g Figuresjn ald 1 0.. aresxeatly 'effllrged Sttional views showing the i differentv rollers Vby which the preformed materialfisfgided "land seamed as it Wraps around-the mandrel.-

are# tiene Figure 11 is an enlarged view, partly` broken away and partly in section, offV the trip "forrriin'g rol-1.assembly shown in Figure 1, i .Figure 12 is an `'enlarged sectional 'vievjtaken on the line I2-l2'of Figure 11, 3

AFigure 1 3is a side elevation, partly'in Section, showing av modied y forming roll assembly vthat can beusedjin place of the vstructure shownin Figure 15 is a side elevationion areduc'ecl scale, showing the IWay in which vthe formingroll assembly of Figures l 3and 1 4 is assembledfwithfthe .frame of themachine shown-in Figure '71, when this A modified forming roll assembly is jusedfyin place of the A forming roll assemblyfof Figuregl.

The tube making machine includes Y 'a' fixed frame 2 0 that restsupon'a floor orother-spport. vThis frame haS S uitb1 -9Qr1tr01 Switches 2| and r2 2 at the front in position fior' convenient -actuation by the operator "of the,machine;ll There is a. post Y2 3 co rirlecdtgeglWith` the bac-kfl the main framegby brackets '24 25.1";fl'nese brackets andthe post 23 are part'of rtlgeflxed frame' 2li-lof -This Quick change keep 15.21 becom s exh 3 44 bears against the upper portion of the lever 4| above the pivot 42.

As long as the roller 36 and feeler 49 are held apart by the presence of a strip of metal between them, the automatic strip device 38 is ineffective. Whenever there is no strip between the roller 36 and feeler 40, either because of breakage of the strip or the exhaustion of the supply reel on the plate 38, the feeler 40 moves closer to the roller 36 and this motion permits the Vswitch operator 44 to move far enough to operate the automatic stop device and shut off the electric power that operates the machine..

The strip 21 passes upward through feed rollers 46 operated by a motor 41 that supplies the power for paying out the strip 21 from the supply reel on the plate 28. The strip 21 passes upward further to an idler roller 49 supported by. a bracket at one end of a track 50. This track 50 is attachedA to the`fixed frame of the machineby a connection 52 that is adjustable to change the inclination of the track 50. The strip 21, after passing around the roller 49, passes around a guide roller 54 and then through a number of successive roll passes in a forming roll assembly 55,. v Y t The forming roll assembly 55 includes a frame 51 that Aslides on the track 56. In the ordinary operation of themachine, the track`59 is set onan inclination that makes the assembly 55 tend to slide down the incline in a direction away from the guide roller 49. The forming roll assembly 55 is counterbalanced on the track 50 by a weight V|59 connected to the frame'51 by a ribbon or cord 46| vthat passes around a pulley 62 carried by a lug extending upward from the track 50.

AThe forming rolls in the forming roll assembly 5,5 are geared together for operationrin unison and include successive pairs of rolls that comprise .roll stands through which the strip passesI successively. This construction will be described more, fully in connection with Figures and '11, It is sufficient for the present to understand that Vthe forming rolls are driven by a pulley 65 to which poweris supplied by a belt 66 from a smaller pulley 61. This pulley 61 is on a shaft `68 with another pulley 69 that receives power through a belt `1|) from a double-groove adjustable pulley 1|.

`Tl'iebelt 10 runs nin one groove of the adjusth ablerpulley 1| and another belt 13 runs in the other. groove of the pulley 1| and connects this pulley 1.| `with a driving pulley 14 on a jack shaft 15. near the bottom of the machine. shaft .is rotated by an electric motor 11 through reduction gearing, and by pulleys 19 and V8|.'I secured to a reduction gear output shaft Y 8| and the jackshaft 15 respectively.

' position. The movement ofthe bracket 12 about its pivot 84 provides an adjustment for the tension of the belt 13; and the tension of the belt 10 canbe adjusted by raising and lowering a clamp 13 that supports the pulley 61 from the post 23. Y The position of thepulley 65 with respect to the pulley 61 is .correlated with the slope vof the The jack track 59 so that movement of the frame 51 along the track 5|] under the influence of the weight 66 reduces the distance between the centers of the pulleys and 61. This results in a decrease in the tension of the belt 66 so that the belt slips and stops the rotation of the forming rolls in the forming roll assembly 55. Such movement n of the frame 51 can only occur when the strip 2'| breaks beyond the forming roll assembly 55. The movement of the forming roll assembly 55, therefore, under the influence of the weight 66, provides an `automatic stop for cutting on the supply ofY power to the forming rolls whenever the strip 21 breaks beyond the forming rolls.

The strip 21 is pulley from the forming rolls by a mandrel 83. Power for rotating the mandrel is supplied from a pulley 85 on the jack shaft 15,.to apulley 81 through V-belts 88. The motion transmitting connections through which the pulley 81 rotates the mandrel B3 will be described more fully in connection with Figure 4. For 'the present it is sufficient to understand that the mandrel 83 is' rotated continuously and at uniformspeed by the power drive.

There are a plurality of rollers adjacent the mandrel 83 and angularly spaced around the mandrel. In the construction shown there are four rollers 9|, 92, 93 and 94. Each of these rollers is carried by a support'Qt connected by a pivot 91 with fixed extensions 98 ofthe frame of the machine. The supports 96 are movable about the pivots 91 to shift the rollers 9| vto 94 toward and from the axis of rotation of the mandrel 83. This movement is necessary in order to enable the machine to operate with non-circular and polygonal mandrels which have variations in their width at different regions around the periphery of the mandrel. There is a guide, preferably a roller 99, across which the strip passes just ahead of the roller 9|. This guide roller 99 is carried by the same support 96 that carries the roller 9| and is in a definite fixed relation to the roller 9| that causes the strip to always maintain an arc of contact with the roller 9|.

In order always to maintain the strip wrapped around the first roller 9| far enough so that the strip contacts with this roller 9| before wrapping around the mandrel 83, it is necessary to locate the guide roller 99 high enough so 'that its contact with the strip is at an elevation at least as high as the upper limit of the range of the tangents to the roller 99 at the various points of nearest approach of the roller 99 to the mandrel 83. For example, if no tangent to the roller 9|, at its point of nearest approach to the mandrel, ever passes above the elevation at which the guide roller 99 holds the strip, then the strip will never come in contact with the mandrel before contacting with the roller 9|, and this means that the strip is always guided by the roller 9| as the strip reaches the mandrel. This guiding is important because the initial engagement of the edges of the strip with the opopsite edge of the preceding convolution on the mandrel must be accurate to insure tubing having a uniform seam.

vFor makingtubing having a soldered seam, means are provided for feeding a thread of solder toward the mandrel into position to be incorporated into the seam of the tubing at the time that the strip 21 iswrapped around the mandrel to form the tubing. These means include a solder supply roll |00V from which. a thread of solder |0| passes upwardaround guide rolls |02 to* the `mandrel 83. A switch feeler |03 vbears against ya run 'of the solder and actuates'an automatic stop switch in thefevent that the solder thread breaks. The solder'thread vtravels past a iluxing device in a mannerwell understood Ain the art, and no illustration of [the iiuxing device isnecessar'y for a complete understanding' of this invention.v 'f 4' `I n addition to the metal strip 21 and the solder thread'A |0I, a wire |06 is supplied to the mandrel from a `reel |08 near the bottom of the machine; the'wire passing first over a Vertical guide roller I| and then around a horizontal guide roller I'II. The purpose of the wire is to provide a support under the corrugations of the metal strip to prevent these corrugations from being mashed down during the forming of the tubing on the mandrel.

Inrorder to have the wire |06 wind on the mandrel without kinks, the wire is maintained undertensionas it comes to the mandrel. This is done by providing a brake I I4 (Figure 2) which bears against a disc ||5 to supply friction that resists the unwinding of the wire from the reel |08. This brake ||4 is applied by a spring, and the pressure of the brake can be relieved by pulling upward on a pull rod I |1 that connects with a bell crank I8.

The bell crank I8 is supported from the main frame by a pivot |20, and the guide pulley ||9 is carried by the upwardly extending arm of the bell crank ||8. As the pull on the wire |06 increases, the guide roller I |0 is pulled to the right in Figure 2, and this rocks the bell crank IIB in a direction to relieve some of the pressure of the brake so that the wire unwinds more easily from the reel and is under reduced tension. This construction provides an automatic control for maintaining substantially constant tension on the wire as it is supplied to the mandrel.

Figure 4 shows the apparatus for rotating the mandrel 83 and for moving the rollers 92 and 94 to follow the changes in the width in the mandrel. The pulley 81 is keyed to a hollow shaft |24 that turns in bearings |25 mounted in the main frame 20 of the machine. One end of the mandrel 83 is rigidly connected with a cam I 21 and the assembly comprising the mandrel 83 and the cam |21 fits into a socket |29 in an enlarged end portion of -the sleeve |24.

There is a threaded socket |33 in the rearward end of the mandrel 83. A draw bolt |34 extends through the hollow shaft |24 and threads into the socket |33. The rearward end of the draw bolt is threaded to receive a nut |39 which reacts against the hub of a hand wheel |36 to pull the draw bolt |34 rearwardly and to hold the mandrel 83 and cam |21 securely in the socket |29 at the end of the hollow driving shaft |24.

.The hand wheel 36 is keyedrto the driving v shaft |24 and provides a convenient means for turning the mandrel by hand when starting the forming of a new piece of tubing on themandrel, or when adjusting the machine. The mandrel 83 and cam |21 are also connectedwith the driving shaft |24 by keys as will be more fully explained in describing the operation of the cam.

The fixed extensions 98 are connected with another part of the fixed frame 20 by screws |49; and the supports 96'are spaced some distance ahead of the xed extensions 98 by spacers |42 and |43. Nuts |46 threaded over the opposite ends of the pivot 91 heid the assembly together. At the lower end of the support 96, thereis an angle |48 by which a composite bearing bracket 6 |49 is `connected with the support 96. This bea'rl ing bracket |49`is heldin place on the 'angle' |48 by a dowelvpin |50, but the' angular position of the bearing bracket |49 is determined by screws |52 extending through slots" in'the angle |48 and threaded into the composite bearing bracket |49. The roller 94 has .an.axle. |54 connecting it with the bracket |49. All of the other rollers around the mandrel 83 are similarly connected with the other supports 96. l 'l A cam follower,.preferably'a roller |60, is connected with each of the supports 96 and is located in position to contact with'theface ofthe loam |21. This cam |21 is held in a' fixed and definite angular relation to the mandrel 83 by a key |62; and the face of the cam |21 is shaped to maintain the roller 94, and the other rollers that are located around the mandrel, in working relation to the mandrel at all times. Thus the cam |21 displaces the cam follower |60 to move the roller 94 closer to the axis of rotation of the mandrel 83 whenever a portion of the mandrel having a reduced width is moving into position under the roller 94.

The other cam followers |60 cause the other rollers around the mandrel to stay in working relation with the mandrel 83 during its rotation. It is necessary for the cam |21 to move the rollers toward the mandrel only, because the mandrel itself, being non-circular, acts as a cam and pushes the rollers outward away from its axis of rotation whenever portions of the mandrel having greater width are moving into position under the rollers 92 or 94, or the other rollers that are located adjacent the mandrel but not visible in Figure 4.

The roller 94 has a, peripheral surface |65 at the rearward end of the roller for contact with the surface of the mandrel 83. Since this surface |65 is beyond the grooves of the roller that guide the metal strip, and beyond the portion of the mandrel on which the metal strip wraps, it can contact directly with the mandrel and serve as a follower for pushing the roller outward away from the axis of rotation of the mandrel under the cam action of the mandrel.

In the preferred construction, the radius of the face |65 is greater than the radius of any other part of the roller 94 by a value at least as great as the thickness of the metal strip with Which the roller is intended to be used. This makes it possible for the face |65 to touch the surface of the mandrel 83 while the metal strip is being wrapped on the mandrel.

Because of the fact that the roller 94 is free to rotate and therefore has comparatively little friction against the metal strip, it is also practical to rely upon pressure transmitted from the mandrel through the strip to the roller 94 for camming the roller 94, and the other rollers that surround the mandrel, outward away from the axis of rotation of the mandrel, instead of having the peripheral surface |65 of a diameter sufficient to maintain contact with the mandrel. Depending upon the diameter of the peripheral surface and its relation to the diameters of the other parts of the roller 94 and the thickness of the metal strip, the roller 94 will clamp the metal strip tightly against the surface of the mandrel 93 or press and guide the metal strip into a position close to the mandrel as thevstrip is drawn into actual contact with the surface of the mandrel by the tension of the strip approaching the mandrel. The roller. 94y andthe other rollers around the mandrel 83, are said to be in workingl relation withthe-mandrel 83; when they areeither` clamping the; metal strip against the mandrel or-located close enough to the` mandrel to guide and form the tubing as the strip is wrapped around the mandrel by the tension of the approaching strip.

The .brackets |49 are angularly adjusted about the dowels |50 'so as to make the grooves of the rollerv 91 extend in thefsamer direction as the helical seam that is tobeV formed when wrapping the strip on thevmandrel. The roller @Zand the otherrollers around the mandrel are similarly turned, and the correspondingv grooves ofthe successive rollers around the mandrel contact with the strip on themandrel at regions which are spaced axially tocorrespond with the pitch of the helixin which the Istrip is wound. The rollers 92 and S, and the other rollers around the mandrel, are held against axial movement on. their axles, however, so that as themandrelcontinues torotate, the material on the mandrel is progressively stripped from the mandrel as rit forms into a tube.

There is a socket H51 in one end of the mandrel for receiving an extension that can be used to support the tubing as it is pushed beyond the end of the mandrel by the stripping actionv of the rollers 92, 9d and the other rollers around the mandrel. A set screw for holding this mandrel extension in place can be threaded into the opening |69'. This opening |69` is located in a portion of the mandrel beyond the region where the strip is formed into tubing so that the opening through the surface of the mandrel will not affect the wrapping or seaming of the tube.

The guide roller 99 turns on an axle supported by a bracket |10 which is attached to the support 96 by screws |1| It is a feature of the invention that the guide roller 99 is located above a line passing through the point of tangency of the roller 9| on the mandrel 83, or the point on the roller circumference that is closest to the mandrel with constructions that do not have actual contact between the roller 9| and the mandrel 83. The importance cf this feature is that it insures the guiding of the strip by the roller 9| at all times.

It will be apparent that the point of tangency of the roller 9| on the mandrel 83 or the point of the roller closest to the mandrel will vary and will be at different phase angle positions of the roller 9|, that is, at points which arev in din'erent angular relation to the axis of the roller, when the roller 9| swings with its support 96 toward and from the axes of rotation of the mandrel as wider and narrower portions of the mandrel move into position under the roller 9|. The giiide roller 99 is located in position tov wrap the strip 21 around the roller 9| along an arc of contact that includes all ofthe points of tangency, or points ofY nearest approach, of the roller 9| with the non-circular mandrel 83.

In orderto obtain accurate positioning of the cam follower |60 with respect to the roller 94, there is a slot |12 cut in the support 96 between the portions of the support to which the cam follower and roller are connected. The respective distances ofthe cam' |90 and roller 9d from the center of rotation of the mandrel 33 can be controlled by increasing or decreasing the Width of the slotA |12. This is done by means of screws, best illustrated in Figure 7.

There is another lscrew |18 that threads through an opening |19 and that 4presses against the wall on the side ofthe slot |12v opposite the 8 end-of the threaded opening-1' |19; When: this screw |18 is turned in a direction to screw it further into the threaded'opening' |19, the.Y end of the screw pushes against the wall of the slot |12 and spreads the `slot to make it-wider.

It will be evident that the screws |15 and |18 must be operated in such away that one of them does not make the adjustment of the slotby the other one impossible. The fact that the screws |15 and |18 operate in opposition to one another enables an attendant to lock these screws in position by merely yscrewing both of them tightly. into position opposing the other screw.

Figure 8 shows the roller 9| which guides the strip 21 into its initialcontact withthe mandrel 83. There are a plurality ofcircumferentially ex;- tending grooves in the face of` the roller 9|. These include a groove |9| for guiding thewire |06 as it wraps around the mandrel 83. Another groove |82 in thek roller 9| guides the.V flanged edge of the strip 21 as the strip wrapsaround the mandrel. It is a feature of the inventionthat the groove |82 has Isloping faces whichrperrnit the upstanding ange of the preformed strip 2 1 to bend over part way out ofitsoriginalvertical position. This bending over of the flange pref vents the flange from stretching and tearing,v in a way that has been experienced on other tube making machines using non-circular mandrels.

A particular problem is presented by the noncircular mandrel, even though it rotates continuously, because the changes in the radial width of the portion of the mandrel with which the strip has its initial contact cause substantial variations in the rate at which the strip is drawn to the mandrel. This causes an uneven pull on the strip, and with this invention the flange of the strip is relieved of some of the strain resulting from the pulling and bending of the strip by being allowed to bend over part way so that the outer edge of the ange is nearer to the center of curvature of thebend, with the result that the flange does not have to stretch as much.

In order to obtain economically the particular shape desired for the groove |82, the roller 9| is of composite construction with a ring |86 pressed over a reduced diameter portion of the body of the roller 9|, and the inner face of this ring |86 comprises one side of the groove |8|. The roller 9| has ball bearings |88 for reducing its friction as it rotates about its axle |54. All of the other rollers around the mandrel S3 have similar ball bearings, though other types of bearings can be used if desired.

A third groove |93 of the roller 9| guides the folded over edge of the preformed strip 21 into engagement with the flange of the next adjacent convolution of the strip on the mandrel 83. There are other grooves in position to receive subsequent convolutions of the seamed tubing on the mandrel. The roller 9|, and the other rollers that are located around the mandrel 83, act in effect as a roller nut through which the tubing screws as the mandrel rotates. The tubing is thus strippedfrom the mandrel pro.- gressively as it is formed.

Figure 9 shows the roller92. with a groove |9 for the wire |06, and a second groove |92 that bends the ange of the metal strip-back into a substantially vertically extending position. The bending of the ange after the strip is wrapped on the mandrel, and whilethe strip approaches and passes into the groove I9 permits the flange to be returned toV its uprightposition without tearing because the pressure is. applied gradually toward the mandrel and starts the interlocking of the seam. Other grooves |95 correspond with thegrooves |85 of the roller 9| and the side walls'of these grooves vserve to strip the tubing from themandrel, in a manner already explained.

Figure shows the roller 93 with a groove for the wire |06 and a groove 202 for guid ing the flanged edge Aof the metal strip and advancing the strip axially along the mandrel 83 in accordance with the progressive stripping action of the rollers previously explained. The next groove 203 is shallower than the corre-y sponding groove |93 andtheprevious roller 92. Thegroove 203 is preferably shallow enough to bend the folded edge of the strip and its engagingflange all the way down to form an interlocked seam for the tubing, and the bottom of this groove 203 preferably rolls the interlocking seam against the vwire |06 on the mandrel. wire prevents .the corrugation under the seam from being mashed down by the seaming oper-I ation..V Y

@The solder thread 10| is enclosed within the seam and is fused subsequently after the tubingis-stripped from the mandrel.. Other groovesy rolls are indicated by the reference character 209'. The upper and lower rolls 208 and V213i] are secured to axles 2 and 2I2 respectively. There is a gear 215 keyed to each of the upper shafts 2H; and there is' a gear 2|1keyed to each of theV lower shafts 2|2. These gears 2|5 and 2|1 foreach pair of complementary forming rollsl mesh vwith one another. Idler gears 2|9 disposed betweenthe gears 2|1, connect the d ierent roll standsfor operation inv unison.

A driving gear 22| located between the second and v.third lpairr of forming rolls meshes with the gears 2|1 onl opposite sides o f it. This driving gear 22| is connectedfwith a drive shaft 223 (Figure 12) which is rotated by the pulley 65.

Theaxles 2|| and 2|2 are supported in ball bearings 225. The upper ballbearings 225 are carried. in blocks 226 which are adjustable in the frame 51 1whichhold down screws230 for regu-y lating the gapv between .each of the upper, forming rolls 208 and its `complementary lower formy ingroll 209. The rearward endsl of the axles 2| -and 212 arecarriedin ball bearings 23| held in'the frame 51.

yThe sides ofthe frame of the roll assembly 55 arev secured together attheir upper and lower ends by a top prato 233 and a bottom mato 2st,A

respectively; and these plates are connected with the sides of the frame byscrews 235. For V initially threading the strip 21 through the successive roll stands of Ithe vroll assembly 55, there The is a largehand wheel 238 attached tothe end 240 `attached to; the bottom plate234 serve as runners on which the roll assembly 55 is movable along the track 50.

Figure 12 shows alsothe connection of the pulley with the shaft 223. The portion of the pulley that is rotated by the belt 66 is free to turn on the shaft 223, but the shaft 223 is secured to a flange 242 by a setscrew 243, and a friction clutch disc 245 is located between one side wall of the pulley 55 and the confronting sidewall of the flange 242. AThe pulley is urged against this fr1ction clutch disc 245 by another flange 2 41. which is located on the other side of the pulley 65 and which transmits pressure lto the pulley- 55 through another friction clutch disc 248.

TheA pressure with which the pulley v(i5 is clamped between the flanges 242 and 241 is determlned by a spring 25u compressed between the hub of the clutch flange 241 anda washery and 241, and the parts clampedvbetween them,`v

is correlated with the forming rollers .201 and 200, and with the size and hardness or stiffness ofthe strip 21 so that the driving. clutch.

will slip before it supplies enough torque to drive the forming rolls. Additional power must be supplied by turning the mandrel, and pullingr the strip toward the the mandrel.

In the preferred construction, the pulley 65 and its associated friction clutch are made so `mandrel' as it wraps on that they will supply approximately two-thirds,

of the torque required for advancing the strip 21 through the forming roll assembly 55. The

power driving connection to the forming rolls greatly reduces the tension in the run of the strip between the forming roll assembly and the mandrel, but some tension Ain thestrip'is desirable.

Figure 13 shows a forming roll assembly'260 that can be used in place of that shown in Figures 11 and 12, if desired. The forming roll assembly .contains only idler rolls, and the strip 21 is advancedthrough theseforming rolls entirely by the tension imparted to the strip by the wrapping action of the mandrel. This forming roll assembly is suitable for small or light gauge strip but for strip that requires substantial power to form it, the roll assembly of Figures 11 and 12 is preferred.

vThe forming roll assembly 260 includes upper forming rolls 263 on axles 254;' and lower forming rolls 266 on axles 261.` The axles 261' are fixed with respect to a main frame 268.

along a groove in a track 212 Each of the axles 284 is Supported from a This frame `has a dovetail slide 210A which runs block 215. which swings about a pivot 218.` The.

block 215v can Vbe urged by a coil spring280, to rock leither clockwise or counterclockwise about its pivot 21a.v The force of this springV 280is exerted througha roller 282 that Vis .movable to either the right or left of the pivot 2.18.

This. shifting of the spring 280 and roller282 is eected by swinging a tubular'. housing. 284, 1n vwhichV the spring 2 80 Lis enclosed, about'a In the illustrated.

Il pivot 286 that connectsA the spring housing 284 with theframe 268'of the forming rolll assembly. Each of the rollers 282 is carried by an axle atthe forked lower endof a block 288 that slides in the bottom portion ofthe tubular spring housing 284. This block 288 has a slot 2907extending through it, and the pin 286, which connects the tubular spring housing 284 with the frame 288., extends through theV slot 290 and prevents the block 288 from rotating. The upper end of the. spring 280 contacts with a plug 292 threaded in the upper end ofthe spring housing 284. The plug 292 has an opening 295 through which a tool can be inserted for unscrewing theV plug 292A if it sticks in the spring housing.

In Figure 13 the left-hand spring housing is inposition to apply the pressure of the roller- 282 against a portion of the block 2.15 slightly to the right of the axis of the pivot 218 about whichthe block 215 swings. This separates the rollers 263 and 266.

The next spring housing 284 is shown in a different position in which it causes the pressure of the spring 289 to be applied to the block 215 on the left-hand side of` the axes of the pivot 218 so that the upperforming-roll is urged toward the lower-forming roll. There is an adjustable stop screw 298 in each of the blocks 215. These stop screws extend beyond the lower end of the. blocks 215 and strike against the portions ofthe frame 268 below the blocks to limit the minimum clearance between the upper and lower rolls 2.63 and 266. 1

Figure 15 shows the way inwhich the manually releasable forming roll assembly 269 is mounted on the track 212 with the adjustable connection 52 set to give the track-212 anA inclination that will permit the entire forming roll assembly 2.60. to. move upward under the pull of the weight 60 whenever there is a break in the. strip. 21 between theforming roll assembly. and the mandrel. This movement of the forming roll assembly 260, along the track212, canrbemade to operate a switch to shutoi the supply. of electric-power to the machine in the event of such a breakin the strip.

The preferred embodiment of the invention and some. modiicationshaverbeen described, but

changes and other modifications can be made,V

andsome features can be used alone or inV different combinations without departing fromY the inventionas defined in the claims.

What is claimed is:

1. A machine for making helicallywound, convoluted tubing including, in combination, a noncircular. mandrel, apparatus for rotating the mandrel, a plurality of rollers angularly spaced around the mandrel substantially in contact with the mandrel and in positions to guide a preformed metal strip and make it into convoluted tubing as it wraps around the mandrel, one or more of said rollers being shaped to seam adjacent convolutions of the-strip, supporting means for at least the one of said rollers with which the strip first, comes into contact as the strip is wrapped around the mandrel, said supporting means including bearings on which the supporting means are movable in directions that shift the rst roller toward and from the axis of the mandrel along a predetermined path as the non-circular. mandrel rotates under said first roller, and a combined guide and arc control element for the formed strip ahead of the iirst roller and in position to hold the formed strip wrapped around- 12' the first roller along an arc that extends beyond` the range of locations at which the mandrel and rst roller most nearly approach one another during the movement of the first roller toward yand from the mandrel along said predetermined path.

2, A machine for making non-circular, convoluted tubing by helically winding a preformed strip, said machine comprising a non-circular mandrel about which the strip is wound, apparatus for rotating the mandrel, rollers around the mandrel that make the strip into a convoluted tubing as the strip is wound on the mandrel, said rollers including a rst roller substantially in contact with the mandrel and that presses the preformed strip into contact with the mandrel,

other rollers angularly spaced from the rst roller around the mandrel in positions to guide and seam adjacent convolutions of the strip, supports by which the rollers are carried and with which the rollers are movable to follow the variations in the width of the non-circular mandrel, said supports including bearings that confine the: movement of the rollers to predetermined paths and a combined guide and arc control element for the formed strip ahead of the first roller and in position to wrap the strip around the first roller along an arc of contact that includes all of the points on the circumference of the rst roller that becomes tangent with the surface of the mandrel as the :first roller moves along its predetermined path to follow the variations in the radial width of the portion of the mandrel immediately adjacent to said first roller.

3. A machine for making flexible metal tubing including a non-circular mandrel, apparatus for rotating the mandrel, forming rolls that shape a metal strip with a fold along one edge` and an upturned flange along the other edge, a roller adjacent the mandrel in position to cause the preformed strip to wrap around the mandrel in a helix, a support for said roller movable toward and from the axis of rotation of the mandrel along a, predetermined path, means for causing the roller to move with said support as the width radial of the mandrel under the roller changes during rotation of the mandrel, a guide that fits the preformed strip on the opposite side` of the strip from the roller and that is located between said roller and the forming rolls in a position to deiiect the run of strip between said roller and the forming rolls in a directionl to wrap the strip around an arc of said roller, said arcbeing at least long enough to include all of the points on the circumference of the roller that becomes` tangent with the surf-ace of the mandrel as thev roller moves along said predetermined path while following the variations in the radial width o f the mandrel and other rollers located around the mandrel and angularly spaced in positions to guide successive convolutions of the strip and to interlock the folded and anged edges of successive convolutions to form ahelical seam.

4. A machine for making flexible, convoluted metal tubing including a non-circular mandrel, a roller adjacent the mandrel in position to cause a preformed metal strip to wrap in a helix Iaround the mandrel, a support for said roller, a bearing on which said support moves about an axis that,

is parallel to and fixed with respect to the4 axis of rotation of the mandrel, means for causingv the roller and its support to follow the mandrel as angular regions of the mandrel of greater and lesser radial width moveunder the'roller, other rollers angularlyspacedaroundthe mandrel for guiding and .seaming ladjacent convolutions together, and a combined guide and arc control element for the formed strip located adjacent the rst roller invposition to bear against the strip onfthe opposite side of the strip from the nrst roller before the strip reaches the'rst roller, and at a position that holds the strip against the 'circumference of the l first roller-along an arc that isat least long enough to'include at all times the point on the circumference of therst roller that is jnearestjto the mandrel asthe nrst roller swings about'the axis of its support' to `follow changes in the radial width ofthe mandrel'.

' 5'. Afinachine for making helically seamed,` non-circular tubing, said machinev including 'a mandrel having the desired' cross section of the tubing, mechanism forvrotatingfthe mandrel, a pluralityA of rollers located at angularly spaced regions around the mandrel in position to'guide a` strip and lseamy it as saidstrip wraps around the mandrel'inahelix, a separate arm by which' each roller 'is carried', a pivot about which each armswings' a'cam follower connectedvvith each armband"located near the same end of the arm as the roller," a "cam having a displacement 'surface'upon which the followers,` run and by which` each 'followerand itsassociated r'oller and arm assemblyis Adisplacedtoward theraxis of the mandrel"'as1pcrt` ions ofy the mandrel having reduced radial thickness comeunderthe respective rollers, thel surfaces of the non-"circular mandrel itself comprising a `seconelf'eam,thatjcooperates with each, roller, cam follower'and 'arm vassembly to move it awayl from the axis ofthe mandrel as portions of the mandrel having greater' radial thickness come under thev respective rollers, means on the arms adjustable to change the spacing of the axes of the cam follower and roller with respect' to oneanother on the respective arms'f'and cam 'driving means ,that rotate the mandrel" and'cam in constant phase angle relationfwithjone another.

' 6;" Apparatusr for making' non-circular tubing including, in combination, a fixed frame, a, none circular mandrel, bearings in the'frame in which the mandrel is rotatableabout an axis, a plu rality of 'rollers located` at angularly spaced regions around the mandrel for Y guiding and bending a metal strip as 4itwwraps around the mandrel; 'supportswithA which' the rollers are movable toward and from the axis'of the mandrel to follow the vari-ations inthe shape of the mandreLcam followers connected with said sup,- ports' and each of which comprises a `unitary assembly with its associated support and roller, there being a separate cam follower for each support and said cam followers' `being angularly spaced around the axis of the mandrel and havingitheir axes generally in,l alignment withfthe axes of thev respective rollers,. aI cam thatrsurrounds the mandrel and that has-an inside displacement 'surface on whichjthe'cam followers run,"said cam having changes in contouricorresponding to the changes i'nradial width lof the mandrel to'move the rollers toward the mandrel during periods lwhen the 'ra'dial'width o-f the mandrel under the respective rollers is decreasing,v

the surfacesiof the non-circular -mandrel itself comprising a second cam that cooperates with each roller, cam follower and arm assembly to move it away fromthe axis of the mandrel as portions of the mandrel having greater radial thickness come under the respective rollers, mechanism that drives the mandrel and cam with a continuous rotation at the same speed and at with which thestrip has contact'ibefore reaching the other rollers, peripheral grooves in said'rollers shaped to wind the strip around the mandrel in a helix, toguider the foldededge of' one convolu" tion into engagement with lthe ange of the adjacent convolution and to bend the engaged flange and folded edge tov form'aninterlocked helical seam, other peripheral rgrooves inr therollersbeyond the strip guiding and-bending grooves for stripping the tubing progressively from'the mandrel 'as the tube'is dformed upon the'mandrel; guide means that control the movement of both the formed strip and a wire to the first of said y rollers, the guide means being located in Contact Awith the strip and wire at lleast as'high as the upper limit offtherange of tangents to the r's't roller atl its various points of nearest "approach to the mandrel, other'peripheral grooves inthe rollers ahead ofthe strip 'guiding and bending grooves andin positionsto causet'he wire to wrap as a helix around the mandrel and to advance the wire into position to support'the seam in spaced relation to the mandrel beyond' the initial` convolution of 'the wire.

- 8'. A machine for making helicallywoundycor-` rugated metal tubing, including a mandrel', appa'- ratus for rotating the mandrel, 'a .pluralityroif rollers located adjacent the" mandrel and angu'e; larly spaced' around the mandrel,y peripheral grooves in the'rollersguiding a lpreformed strip that has ra turned up flangealong one sidev and a folded edge along the other side and alongitudinally extending corrugation between thel oppo# site sides' of thejstrip, other grooves inthe rollers for guiding a wire to wrap the wirev in'acon'voluV tion ahead of the metal strip-said other grooves of the successive rollers havingsidewalls that advance the wirealong the mandrel'into"position'y to be covered'b-ya convolution of 'the metal stript upon the next revolution of the mandrel',av supply reel from which wire is payed out to 'thernandrel| a brake on thesiipply reel, and a deviceI respon-` siveto the pull onv the wire for controlling 'the force with which' the brake is applied tothe sup#L 9. Apparatus for making sexis-ie tubing includ-'f ing a rotatable mandrel,v a plurality of 'rollers angularlyspaced around the mandrel andV in position to cause a preformed strip .to wrap in `'a helix aroundl the mandrel and form 'tubing' having anV interlocked seamand a helical corrugatiom appa ratus for supplying a wire to the mandrel inposi; tion to wrap ina helix around the mandrell and to support the helical corrugation -ofythe tubing during thev interlockingv of the seam and to.l brace the. helical corrugation againsty forcesused to strip the tubing from the mandrel, a brake" gere-eee 1'5 force Vin proportion to the extent' to which the wire is deflected by said element.

10. In a machine for making helically wound, non-circular tubing, a roller that guides -a strip into its initial Contact with a non-circular mandrel as the mandrel rotates to Wrap the strip around it, a guide located adjacent to said roller in position to Wrap the strip around an arc of the roller, a common support for the roller and guide, a bearing on which said-support is movable to shift the roller along a predetermined path-toward and from the axis of rotation of the non-circular mandrel, the arc of contact being at least long ,enough to include each and every pointon the circumference of the roller that is closest tothe mandrel at various times as the roller moves along said predetermined path to follow the diierences in radial thickness of the mandrel.

l1. In a machine for making helically wound, iiexible metal tubing from a preformed strip having a longitudinally extending corrugation between its edges, a mandrel about which the strip is wrapped as a helix with successive convolutionsin overlapping relation, a roller adjacent the mandrel in position to guide the strip into its contact with the mandrel, a strip guide immediately ahead of said roller and in contact with the -strip at an elevation at least as high as the upper'limit of the range of the tangents to the roller at itsvarious points of nearest approach to the mandrel, grooves in the roller and guide for guiding the strip, and other grooves in both the roller and guide for guiding a wire to the mandrel one convolution ahead of the strip.

12. Apparatus for making flexible metal tubing, said apparatus comprising forming rolls that bend a metal strip to provide a iiange along one side and a folded edge along the other, and a longitudinally extending corrugation between the ange and folded edge, a mandrel about which the formed strip wraps as the mandrel rotatesy a plurality of rollers adjacent the mandrel and angularly spaced around the mandrel, a peripheral `groove in at least the iirst of the rollers for v guiding the strip to wrap it as a helix. around the mandrel with the flange of one convolution engaged in the folded edge of the next adjacent convolution, a peripheral groove in another roller imposition to bend the flange and folded edge into an interiocked seam, said rollers having other grooves extending in such directions and in such correlation with the corresponding grooves of the respective rollers that they strip the tubing from the mandrel progressively as the tubing is formed,

guide means immediately ahead of the nrst roller in contact with the strip at least as high as the upper limit of the range of the tangent to the rst roller at its various points of nearest approach to the mandrel, other peripheral grooves in the rollers, ahead of the grooves that engage the strip, in position to guide the wire to wrap as a helix around the mandrel, said other peripheral grooves of the respective rollers being in correlated positions for advancing the convolutions of the wire axially along the mandrel at the same rate that the convolutions of the metal strip are advanced by the stripping action of the rollers.

13. In a machine for making corrugated, helically wound, exible tubing, a non-circular mandrel about which a strip of metal is wound, means for rotating the mandrel,a forming roll assembly through which the strip of metal is pulled by the Wrappngfof the istrip on the -mandreL-a frame tliatvsupports the form'ing'rolls of saidfassembly, atrack along which'the frame is movable, said track extending in a direction that Vhas a substantial component in the direction in which the strip travels from the forming roll assembly toward the mandrel, and yieldable means that'continuously opposes any force urging the frame to move along the track in the direction of thepull vof the strip as lthe strip feeds from the formingroll assembly toward the mandreLthe force of said yieldable means in the direction of the mandrel pull being of a magnitude between the maximum and minimum pull on the-strip as the radial thickness of the mandrel changes at the point of initial wrap of the strip on the mandrel.

le. A machine for making tubing by Wrapping a formed strip varound -a mandrel, said machine comprising a nxed frame, apparatus for rotating the mandrel with respect to the xed frame, 'a forming roll assembly movable toward and'from th@` mandrel and through which a strip of metal passes on its way to the mandrel, a track along which the forming roll assembly is movable, a pulley carried b-y the forming roll assembly for supplying power to the rolls of saidassembly, a belt for driving the pulley, and another pulley that drives the belt and that is located on the iixed frame in such a position that movement of the forming roll assembly Valong the track`aw`ay from the mandrel loosens'the beltbetweenvthe pulleys, and means urging the forming roll assembly to move along'the track vin the direction away from the mandrel so as` to loosen the belt stop the supply of power to the rolls of said assembly whenever there is no pull on the strip between the mandrel and the 'forming roll assembly.

15. Apparatus for making helically seamed, non-circular corrugated ltubing from a metal strip, said apparatus comprising a non-circular mandrel about which'thestrip is wound in a helix by the rotation of the mandreL'forming rolls between which the strip passes Vto the mandrel and by which the strip is shaped to a desired transverse contour, driving mechanism that rotates the non-circular mandrel at substantially constant angular speed with resulting variation in rate of speed at which the strip is pulled through the forming rolls, which speed is dependent upon the changes in the radius of the mandrel at the region where the strip starts to Wrap the mandrel, other power driving mechanism for the forming rolls including friction clutch means that slip when the strip in the forming rolls is not subjected to supplemental power by the pull of the strip by the mandrel, the driving mechanism Vfor the forming rolls including mechanism that rotates the driving element of said friction clutch means at a rate to give the strip a lineal speed through the forming rolls equal to the maximum rate of pull of the mandrel, a 'carriage by which the forming rolls are supported, a track along which the carriage is movable toward and from the mandrel, and means urging the carriage to move along the track in a direction away from the -mandrel with a predetermined force that yields whenever a greater force isexerted in the opposite directionby theipull of the strip from the mandrel.

l5. The apparatus described in claim 15, and in which the clutch means of the power driving mechanism 'for the forming roll includes a friction disc clutch with elements 'that slip Aon one 'another fat'-'a torque less than-that lrequired'fto drive the forming rolls with the strip between them 17. Apparatus described in claim 15, and in which the forming rolls comprise a plurality of rolls supported by the carriage in position to provide successive roll passes through which the strip travels, driving gears connected with the respective rolls, intermediate gears between the roll driving gears connecting the roll drive gears of the dierent roll stands for operation in unison, and a power shaft on the carriage and connected with one of the gears, and in Which'the clutch means include a clutch that drives the power shaft, said clutch including driving elements that slip on one another at a torque that is less than that required to drive the forming rolls with the strip between them and with no pull from the mandrel.

PHILIP M. PADGETT.

REFERENCES CITED The following references are of record in the le of this patent:

Number Number 18 UNITED STATES PATENTS Name Date Kelly Apr.'22, 1890 Frankenberg Aug. 14, 1905 Wilkie July 19, 1910 Lombardie May 12, 1914 Brinkman Sept. 12, 1916 Brinkman June 28, 1921 Bourn Jan. l5, 1924 Peyser Oct. 28, 1924 Palmer Aug. 17, 1926 Johnson Feb. 24, 1931 Troyer et al June 5, 1935' Stone Aug. 23, 1938 Parrish June 13, 193,9; Shellmer May 30, 1944 Carter Sept. 3, 1946 Viehweger June 17, 1947 Wyllie May 4, 1948l FOREIGN PATENTS Country Date Australia of 1910 

